The influence of boron content to the high-boron iron-based alloys

Nov 6
07:21

2012

David Yvon

David Yvon

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High boron iron-based alloy is a new type of wear-resistant materials. Boron, carbon are important elements that decided borides and matrix, its content plays a decisive role in the organization and performance.

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Use orthogonal experimental method to study,The influence of boron content to the high-boron iron-based alloys Articles the mass fraction of boron from 1.5% to 2.5%, the mass fraction of carbon change and its impact on the hardness and impact toughness of high boron iron-based alloy from 0.2% to 0.5%, the studies provided the basis of the materials.

Boron as an alloying element in steel applications did not have a long time, the first industrial application of boron as an alloying element in 1934, aims to increase the steel hardenability. People study found that trace amounts of boron powdercan greatly improve the hardenability of steel and other precious elements such as chromium, nickel, manganese, etc want to achieve the same effect, the content must be several times or even a hundred times than boron. Boron as alloying elements to improve the hardenability, the content in the steel is low. When the mass fraction of boron exceeds 0.01%, the tissue appears in the brittle borides, the toughness of the steel is lower. Boron is relatively rich content of an element in the earth's crust, as an alloying element to apply, you can save a lot of precious elements, have a positive meaning in industrial production.

High-boron-iron-base alloy is a new wear-resistant material, which contains a wear-resistant phase boride, similar to material is a white cast iron. Currently, the researches about wear-resistant materials containing carbide wear-resistant phase is more, but relatively little research on containing borides wearable phase of wear-resistant materials. On the basis of such material, it is also desirable to be able to reduce precious elements added in the case of wear resistance does not drop, reducing material costs. Such materials in design ideas is the content of boron in the steel is controlled at between 0.5% to 3.8%. Due to the extremely low solubility of boron in iron (boron is less than 0.0004% of the solubility of the ±-Fe, ³-Fe a solubility of only 0.02%, so most of the added boron formed borides, borides, having a very high hardness (such as boron and iron generated Fe2B hardness HV1400 ~ 1500) and thermal stability and is therefore a good wear phase by adjusting the carbon content at the same time to control the microstructure and properties of the matrix, to obtain a good overall performance of wear-resistant materials.

The mass fraction of the high boron iron-based alloy of boron is generally in the range of 0.5% to 3.8%, a hypoeutectic alloy. In cast condition, Organization composed of borides ferrite and pearlite three-phase. In the organization ferrite with the form of irregular lumps, distributed around the boride that this distribution characteristics may be related with the alloy 910  peritectoid reaction; the boride was continuous network ledeburite morphology, the base body is divided; pearlite in the boride and the ferrite between the two phases, the number of the carbon content and the type and content of other alloying elements. Studies bymetal powder supplier suggest that for the wear-resistant material having a wear-resistant phase, the volume fraction of its abrasion should be within the range from 20% to 30% to have a better abrasion resistance. Borides content is determined by the content of the boron in the alloy, macro-hardness of the material is determined by the hardness of the hardness of the matrix and borides content. Boride is a compound of the rigid substrate, is the source of the material toughness, the properties of the matrix by the carbon content of the greatest impact, while the number and distribution state of the boride will also have an important impact toughness of the material, therefore boron, carbon are the two most important elements that determine the basic performance of the high-boron iron-based alloys, its content to the organization and performance of high-boron iron-based alloys is the basis of researching this material.

Source:http://www.mhcmp.com